In recent years, with the virtualization of open systems and servers, management of systems is becoming complicated. Consequently, using storage systems becomes common in terms of easily managing the systems or flexibly coping with a rapid increase in an amount of data.
In the storage systems, performance adjustment of the storage systems is performed by adjusting band limit widths of data transfer paths between, for example, volumes and a server that executes an application. In a conventional technology, adjustment of the band limit widths is performed by a storage system received an instruction from an administrator.
Furthermore, as a technology for adjusting the performance in a storage system, there is a conventional technology that estimates a use capacity for each axis area group by using both a load threshold and past information on pool status information representing both the allocation with respect to a disk pool and the load. Furthermore, there is a conventional technology that has the minimum band of a storage area, that calculates, when the storage area has already been allocated to a selected interface, the sum total of storage areas acquired from an access ratio, and that performs allocation if the access ratio does not exceed 100% even if the band of the storage area to be created is added.    Patent Document 1: International Publication Pamphlet No. WO 2011/092739    Patent Document 2: Japanese Laid-open Patent Publication No. 2007-323284
However, in the method that specifies each of the bands to be allocated to individual volumes, if a target performance is manually set for each volume in order to limit the band, the setting of the band limit is complicated and thus it is difficult to efficiently use the bandwidth. Furthermore, if a bandwidth of a single volume is adjusted, contention occurs with another volume when data is transferred and the load applied to the other volume is increased, which may possibly result in a decrease in the performance.
Thus, it is conceivable to automatically adjust the band by using the most recent data; however, because band limitation is performed by using the most recent data, the bandwidth is gradually decreased. Consequently, it is difficult to efficiently use the bandwidth.
Furthermore, when using the conventional technology that estimates a use capacity for each axis area group by using both the load threshold and the past information on the pool status information, the performance adjustment is implemented by allocating storage areas with different performance; therefore, it is difficult to efficiently use the bandwidth. Furthermore, with the conventional technology that performs allocation unless the access ratio exceeds 100% even if the band of the storage area to be created is added, a user sets the value of the capacity of the resource. However, with this method, the setting of limitations to be performed is complicated and thus it is difficult to efficiently use the bandwidth.